From: Ruslan Valiyev Date: Tue, 3 Mar 2026 11:27:54 +0000 (+0000) Subject: media: vidtv: fix NULL pointer dereference in vidtv_channel_pmt_match_sections X-Git-Tag: v7.1-rc1~169^2~161 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f8e1fc918a9fe67103bcda01d20d745f264d00a7;p=thirdparty%2Fkernel%2Fstable.git media: vidtv: fix NULL pointer dereference in vidtv_channel_pmt_match_sections syzbot reported a general protection fault in vidtv_psi_desc_assign [1]. vidtv_psi_pmt_stream_init() can return NULL on memory allocation failure, but vidtv_channel_pmt_match_sections() does not check for this. When tail is NULL, the subsequent call to vidtv_psi_desc_assign(&tail->descriptor, desc) dereferences a NULL pointer offset, causing a general protection fault. Add a NULL check after vidtv_psi_pmt_stream_init(). On failure, clean up the already-allocated stream chain and return. [1] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:vidtv_psi_desc_assign+0x24/0x90 drivers/media/test-drivers/vidtv/vidtv_psi.c:629 Call Trace: vidtv_channel_pmt_match_sections drivers/media/test-drivers/vidtv/vidtv_channel.c:349 [inline] vidtv_channel_si_init+0x1445/0x1a50 drivers/media/test-drivers/vidtv/vidtv_channel.c:479 vidtv_mux_init+0x526/0xbe0 drivers/media/test-drivers/vidtv/vidtv_mux.c:519 vidtv_start_streaming drivers/media/test-drivers/vidtv/vidtv_bridge.c:194 [inline] vidtv_start_feed+0x33e/0x4d0 drivers/media/test-drivers/vidtv/vidtv_bridge.c:239 Fixes: f90cf6079bf67 ("media: vidtv: add a bridge driver") Cc: stable@vger.kernel.org Reported-by: syzbot+1f5bcc7c919ec578777a@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=1f5bcc7c919ec578777a Signed-off-by: Ruslan Valiyev Signed-off-by: Hans Verkuil --- diff --git a/drivers/media/test-drivers/vidtv/vidtv_channel.c b/drivers/media/test-drivers/vidtv/vidtv_channel.c index da20657adc747..5f8c3af871711 100644 --- a/drivers/media/test-drivers/vidtv/vidtv_channel.c +++ b/drivers/media/test-drivers/vidtv/vidtv_channel.c @@ -341,6 +341,10 @@ vidtv_channel_pmt_match_sections(struct vidtv_channel *channels, tail = vidtv_psi_pmt_stream_init(tail, s->type, e_pid); + if (!tail) { + vidtv_psi_pmt_stream_destroy(head); + return; + } if (!head) head = tail;